C Program to determine whether the angle is Right Angle or Acute Angle

#include
#include
void main()
{
int a;
printf("/n enter value of a");
scanf("%d",&a);
if(a>180)
{
printf("Not valid");
}
else if(a==180)
{
printf("Straight line");
}
else if((a>=90)&&(a<180))
{
printf("Right angle triangle");
}
else
{
printf("acute angle");
}
getch();
}